This volume describes an extensive study of the efficiency of homes for the mentally disabled in the Netherlands. It sets out the theoretical and empirical background to the research, which employs both a parametric (cost function model) and a non-parametric (Data Envelopment Analysis) method to enhance the robustness of the results. The technical details of both methods are discussed extensively. The book also contains a bibliography on these issues and makes useful reading as an introduction to efficiency measurement. The book gives details of the empirical implementation of both methods. An extensive description of the data illustrates the developments in the sector in recent decades. A discussion of various aspects of the production structure, such as scale effects and marginal costs, provides an insight into the performance (efficiency) of the homes. In addition the study looks into explanations of efficiency differences and changes in productivity. The conclusions of the study as they relate to policy are also summarized. This book is another example of the excellent research carried out by the Social and Cultural Planning Office of the Netherlands (SCP) in the past fifteen years on the productivity and efficiency of public services. A policy-oriented publication is also available (in Dutch) on this research (Verstandig verzorgd, SCP-publication 2001/4).